Since her US Open breakthrough, Duval has been sharing her time between the ITF Circuit and qualifying for WTA main draw events, and she arrives in California at a career-high No.139 in the rankings following a run through qualifying and into the second round in Acapulco.

As promising as her showing in México was, Duval's best days surely lie ahead, something Kleybanova is fighting hard to show applies to her too. Three years ago, Kleybanova was ranked inside the Top 20 only for her charge up the rankings to be placed on hold when she was diagnosed with Hodgkin's lymphoma. The Russian, who made the last eight here in 2010, has struggled so far this season, registering just two main draw wins in five tournaments.

Despite her undoubted gifts, the Frenchwoman struggled to deal with the weight of expectation over the following years, which were spent, for the most part, hovering outside the Top 100. Recent weeks, though, have seen signs of real progress, most notably in Acapulco, where she reached her maiden WTA semifinal.

Just how far she has come will be tested when she takes on Bethanie Mattek-Sands and her refreshingly adventurous brand of tennis. The American's attacking instincts, though, have never served her well in the desert, where she has made the second round just five times in 11 visits.

Stadium 4Elina Svitolina (UKR #43) vs. Monica Puig (PUR #57)Head-to-head: first meetingMonica Puig certainly talks a good game, and her exploits on tour over the past 12 months have proved that this is anything but empty rhetoric. This combination of impressive results, highlighted by a fourth round run at Wimbledon, and a bubbly personality have seen the Puerto Rican rapidly carve out a reputation as one of the WTA's brightest young talents.

In the opening round, she takes on a player whose career is heading in the same direction: Elina Svitolina. While Svitolina may not quite have matched Puig's performances at tennis' showpiece events, she certainly knows how to win, as she showed last summer in Baku, where she picked up her first WTA title.

Both players are solid from the baseline, quick around the court and only too happy to adopt the role of counterpuncher, and their first meeting on tour has all the ingredients to be a long one.